NANNOPUS. 101 



the posterior margins. Anterior antenn-se short, 6- 

 jointed (?) ; outer branches of all the swimming-feet 

 3-jointed ; inner branches of the first and second 

 pairs 2- jointed, short, non-prehensile, of the third 

 and fourth pairs obsolete and reduced to a single seta. 



1. NANNOPUS PALUSTHIS, nov. sp. PI. LXXYII, figs. 



1820. 



Anterior antennae very short and stout, scarcely 

 half as long as the cephalic segment. Terminal seta3 

 of the outer branch of the first and second feet strongly 

 and distantly plumose ; inner branch not half as long 

 as the outer, first joint fringed with setae at the apex, 

 second having three terminal setae. In place of 

 the inner branch of the third and fourth pairs is a 

 small tubercle, which gives attachment to a long 

 plumose seta and two or three very small cilia. 



I have seen only one or two specimens of this species, 

 which were so coated with mud that it was difficult to 

 get a distinct view of the limbs, nor did I at first 

 recognise anything very noteworthy about them, else 

 possibly a little extra care might have enabled me more 

 fully to elucidate their structure. There seems, how- 

 ever, to be no reason to doubt the complete distinctness 

 of the genus, and I therefore think it best to 

 describe it, even though imperfectly. Its nearest ally 

 is probably Jurinia, Glaus, but in that genus the third 

 and fourth pairs of feet have the inner branches well 



